The relevation model is a fundamental tool in reliability engineering for assessing the effectiveness of redundancy allocation in coherent systems. In this study, we address the problem of allocation of relevations for one or two nodes in a coherent system with independent components to enhance system reliability. We establish results concerning the usual stochastic and hazard rate orders for coherent systems. Moreover, we illustrate our findings with a range of examples and counterexamples. In addition, we conduct a simulation-based study and a real data analysis to further illustrate the application of our results. Lastly, we study the case of the minimal repair policy in detail.

This article proposes and studies two Huber-type estimation approaches, namely, the Huber instrumental variable (IV) estimation and the Huber generalized method of moments (GMM) estimation, for a spatial autoregressive model. We establish the consistency, asymptotic distributions, finite sample breakdown points, and influence functions of these estimators. Simulation studies show that compared to the corresponding traditional estimators (the two-stage least squares estimator, the best IV estimator, and the GMM estimator), our estimators are more robust when the unknown disturbances are long-tailed, and our estimators only lose a little efficiency when the disturbances are short-tailed. Moreover, the Huber GMM estimator also outperforms several robust estimators in the literature. Finally, we apply our estimation method to investigate the impact of the urban heat island effect on housing prices. A package is published on GitHub for practitioners to use in their empirical studies.

This paper uses China’s 2016 Pollutant Discharge Permits System (PDPS) to evaluate its impact on innovation in the food processing industry. We begin by exploring the entry and exit decisions of food processing firms. The findings suggest that stricter environmental enforcement following the PDPS leads to decreased local firm entry but increased neighboring firm entry, indicating that new firms tend to locate in neighboring regions with less stringent regulations. Building upon this pattern, we argue that the PDPS’s positive impact on firm innovation is primarily driven by increased industry agglomeration – a dynamic directly stimulated by heterogeneous regulatory pressures.

The environmental effects of state ownership are still controversial. The ‘reverse privatization’ phenomenon of injecting state capital into non-state-owned enterprises offers a novel perspective to study the environmental impact of state ownership. Using data on Chinese listed companies from 2011 to 2021, this study empirically analyses the impact of state capital injections (SCAI) on firms’ green innovation. Our results reveal that SCAI has a positive effect on the quantity and quality of green innovation, reflecting the net outcome of opposing forces. SCAI promotes green innovation by enhancing firms’ innovative capabilities and willingness, increasing environmental regulatory pressure and reducing managerial myopia, though it may hinder such innovation by exacerbating agency problems and policy burdens. Moreover, SCAI’s positive effects on green innovation quantity and quality are more pronounced for firms with relatively high state capital control, in heavily polluting industries and in less marketized regions.

In a ruling delivered on 1 August 2025, the Court of Justice upheld a General Court judgment annulling the classification as a suspected carcinogen of titanium dioxide in powder form containing at least 1% of particles of a diameter equal to or below 10 μm. Both EU Courts criticise the scientific assessment underlying that classification, but the Court of Justice relies on conceptual distinctions that reveal its reluctance to perform a genuine “manifest error of assessment” review. While these issues are not addressed by the Court of Justice, the case also raises thorny questions regarding the meaning of “intrinsic properties” of a substance.

The lower Cambrian Cranbrook Burgess Shale-type Lagerstätte (Series 2, Stage 4) occurs within the Eager Formation of southeastern British Columbia, Canada. This deposit consists of claystone intercalated with normally graded mudstone, which has medium silt to very fine-grained sand and disarticulated skeletal debris near the bed bases, recording mostly accumulation from turbidity currents. Well known for its olenelloid trilobites in particular, the site also contains rare soft-bodied fossils, including Tuzoia carapaces and Anomalocaris claws, and low-diversity and low-density suites of ichnofossils. A 2015 systematic field investigation of a 2.65 m interval recovered 12 ichnotaxa and three types of trace fossils left in open nomenclature. The most abundant are Helminthoidichnites tenuis Fitch, 1850, Palaeophycus tubularis Hall, 1847, Diplocraterion isp., and finger-like structures (FLS). These trace fossils form two ichnocoenoses recurring through the studied interval: (1) the Helminthoidichnites tenuis ichnocoenosis, consisting of small trails and shallow burrows, and (2) the Diplocraterion isp. ichnocoenosis, consisting of paucispecific suites of U-shaped burrows, commonly associated with FLS. The FLS contain a diverse range of disarticulated or broken trilobite sclerites and grains coarser than the host sediment and are interpreted as passively infilled burrows, suggesting significant sediment bypass and trapping of transported grains. Overall, the Cranbrook ichnocoenoses do not display a well-defined tiering structure. The trace fossils overall record the activities of a surficial epifauna and a shallow-tier infauna that colonized the sea bottoms during short windows between episodic flows and inhabited dysoxic (Helminthodichnites tenuis ichnocoenosis) to relatively well-oxygenated (Diplocraterion isp. ichnocoenosis) outer shelf environments.

Social media often follow a visual logic found to increase engagement, as images are more likely to attract attention, presenting information on a holistic-associative basis. For a political entity like the EU, social media are a promising route to overcome the remoteness to its citizens, identified as one of the crucial challenges to its public legitimacy. Against this broader background, our study analyses the influence of 10 years of EU visual social media communication on user engagement as an indicator of successfully creating visibility in a crucial communication space. For this purpose, we conducted an image-type analysis, combining quantitative and qualitative features of visual analysis: First, a subsample of posts was inductively analysed to identify recurring image types and subsequently used to implement a manual quantitative visual content analysis. Building on the results, we drew on a machine learning approach, allowing us to analyse over 40,000 posts, including more than 20,000 pictures. Our results emphasise the crucial influence of social media affordances in explaining user engagement with EU visual social media communication. Implications are discussed with reference to the ongoing discussion about the EU’s democratic deficit.

In the 1970s, activists in the Youth International Party transformed new technologies and techniques in the American telephone system into tools for advancing the political aims of the New Left. The Yippies adopted new practices of telephone “hacking” or “phone phreaking” and developed these practices to manipulate, defraud, and protest the AT&T Bell System. Appeals to and protests of “the system” invoked the image of a broader American state. The practice of phone phreaking bridged the technical exploitation of AT&T with critiques of monopoly capitalism, state surveillance, postwar conformity, and American empire. By the late 1970s, as the New Left faded in prominence and the Bell System was itself broken up, the vernacular of system changed. Within an emerging “computer underground” of phreaks, hackers, and users connected through electronic bulletin board systems, the Yippie vernacular of system was reinterpreted as a critique of the state in the language of ascendant conservative and libertarian politics.

Relationships among teachers are known to influence their teaching-related perceptions. We study whether and how teachers’ advising relationships (networks) are related to their perceptions of satisfaction, students, and influence over educational policies, recorded as their responses to a questionnaire (item responses). We propose a novel joint model of network and item responses (JNIRM) with correlated latent variables to understand these co-varying ties. This methodology allows the analyst to test and interpret the dependence between a network and item responses. Using the JNIRM, we discover that teachers’ advising relationships contribute to their perceptions of satisfaction and students more often than their perceptions of influence over educational policies. In addition, we observe that the complementarity principle applies in certain schools, where teachers tend to seek advice from those who are different from them. The JNIRM has the potential to improve the cost efficiency of network studies by integrating network and item response information during model estimation.